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IV.C.1. (XIII.D.1.)

Compare vibrational frequencies in CCCBDB for C4H6O2 (2,3-Butanedione)

mPW1PW91/6-31G

Frequency in cm-1
  Calculated   Experimental
Mode Number Symmetry Frequency diff Symmetry Frequency Comment
1 Ag 3046 28 Ag 3018  
2 Ag 2924 -6 Ag 2930  
3 Ag 1662 -57 Ag 1719  
4 Ag 1422 -2 Ag 1424  
5 Ag 1375 9 Ag 1366  
6 Ag 1264 -10 Ag 1274  
7 Ag 995 -9 Ag 1004  
8 Ag 675 -10 Ag 685  
9 Ag 517 -97 Ag 614  
10 Ag 354 -15 Ag 369  
11 Au 2995 5 Au 2990  
12 Au 1427 6 Au 1421  
13 Au 954 -157 Au 1111  
14 Au 349 10 Au 339  
15 Au 102        
16 Au 53 5 Au 48  
17 Bg 2995 17 Bg 2978  
18 Bg 1431 7 Bg 1424  
19 Bg 1044 -65 Bg 1109  
20 Bg 613 75 Bg 538  
21 Bg 90 -150 Bg 240  
22 Bu 3046 35 Bu 3011  
23 Bu 2924 -2 Bu 2926  
24 Bu 1657 -61 Bu 1718  
25 Bu 1425 4 Bu 1421  
26 Bu 1372 19 Bu 1353  
27 Bu 1120 9 Bu 1111  
28 Bu 914 -13 Bu 927  
29 Bu 524 -10 Bu 534  
30 Bu 232 -18 Bu 250  
The calculated vibrational frequencies were scaled by 0.9466

See section XIII.C.3 List or set vibrational scaling factors to change the scale factors used here.
See section III.B.3.c Calculate a vibrational scaling factor for a set of molecules to determine the least squares best scaling factor.
See section III.B.3.b List of vibrational scaling factors and their uncertainties for information on where the above scaling factor is from.